格式化日期为yyyy-MM-dd

/**
 * 格式化日期为yyyy-MM-dd
 * @param data
 * @returns {*}
 */
function formatDate(data) {
    if (!data) {
        return "";
    }
    var date = new Date(data);
    var year = date.getFullYear();
    var month = (date.getMonth() + 1).toString().replace(/^(\d)$/, "0$1");
    var day = date.getDate().toString().replace(/^(\d)$/, "0$1");
    return year + "-" + month + "-" + day;
}